Solder potting in P60 modules

Hi all,

I have come across the term solder potting for P60 drop-in quite frequently & I finally understood what it meant when I got a mule from Vinh.

So I have a question here; where are the possible places that I can do solder potting in a normal P60 drop-in?
So far the only place I can think of is the pill, on the driver side.
I fill it up with as much solder as I can, just enough so that the driver won't have contact and I fill the remaining gap with the Fujik thermal compound to hold the wires in place.

Are there any other places that I can do solder potting to increase the thermal mass of the drop-in?

Thank you!

While a solder filled pill may help with the ability of the pill to absorb more heat, it doesn't do anything to help transfer the heat from the dropin to the flashlight body. Faster heat transfer from the dropin to the host would be more beneficial as the dropin would run cooler. You can keep adding mass to the pill up to a certain point, but the transition from dropin to the host will be a big bottleneck. Here is the path of heat transfer:

LED->solder between LED & mcpcb->mcpcb->thermal paste/epoxy->pill->reflector->host

A mcpcb without a dielectric layer such as a copper sinkpad would help as well.

A good first step would be to use fujik on the screw threads between the reflector and the pill. From there I would wrap the dropin with copper tape on the reflector. If you wrap the dropin properly and it fits tightly inside the host the heat transfer will be increased by a good amount due to the increased surface area between the dropin and host.

I am aware that solder potting is for the pill to absorb as much heat as possible.
That was my idea because for my usage, I only go high for about 1 min or so.
The rest of the time, I am usually on Med or Low.

I actually wrap all my drop-ins with alu tape to make them fit nicely into the host.
But I am not too sure about the screw thread idea because I thought it might be messy when I want to remove the reflector to make changes or something.
What is your take in that???

When I apply Fujik to the screw threads I use a toothpick to spread a thin layer on the threads of the reflector. When the fujik is dry it is firm but not permanent and its not terribly messy to remove once dried. I use a small flathead screwdriver to scrape off the fujik from the pill and reflector. Once the majority of the fujik is scraped off I use a qtip dipped in alcohol to remove the rest.

If you are constantly removing reflectors then I wouldn't apply fujik as it would be a hassle everytime you remove the reflector. If its once in a while then it wouldn't be that bad. Another benefit of using fujik (besides the increased heat transfer) is that it will hold the reflector firmly to the pill. This can be helpful if you want to dial in the perfect focus point of the pill and reflector.

Yeah, I will probably do that for those dropins I make for my friends.
Since I am sure they don't strip the dropin... Hahaha...

thanks mate, for all your explanations.

How would I go about filling a reflector with solder? Also would putting as much copper wire inside the reflector then filling it give better thermal properties?

SteveoMiami said:

How would I go about filling a reflector with solder? Also would putting as much copper wire inside the reflector then filling it give better thermal properties?

Click to expand...

Steveo,

I assume that you are referring to the base of the reflector, where it meets the pill?

JonK

Sent from my Awesome phone from somewhere in the mountains

No I mean filling the whole reflector except a little bit on top to make a mule from a p60

I see, I'm not looking to make a mule.
I still wanna build the regular P60 dropin module.

JonK

Sent from my Awesome phone from somewhere in the mountains